Folder brakes for forming corners in sheet material



June 15, 1965 H.BARRETT FOLDER BRAKES FOR FORMING CORNERS IN SHET MATERIAL Filed Jan. 29, 1965 4 Sheets-Sheet 1 H. BARRETT June 15, 1965 FOLDER BRAKES FOR FORMING CORNERS IN SHEET MATERIAL 4 Sheets-Sheet 2 Filed Jan. 29, 1965 vnl FIG. 2.

H. BARRETT June 15, 1965 4FOLDER BRAKES FOR FORMING CORNERS IN SHEET MATERIAL 4 Sheets-Sheet 3 Filed Jan. 29, 1963 June 15, 1965 H. BARRETT 3,188,848

FOLDER BRAKES FOR FORMING CORNERS IN SHEET MATERIAL Filed Jan. 29, 1963 4 Sheets-Sheet 4 $8,848 ELDER BRAKES EUR FURMlNG CGTNERS EN SHEET MATERlAL Herbert Barrett, Manchester, Engiand, assigner to The (Biiver Machinery Company Limited, Manchester, England, a British company Filed dan. 29, 1963, Ser. No. 254,749 Claims priority, application Great Britain, dan. 30, wb2, 3,413/62 4 Claims. (Cl. 72-32tl) This invention relates to folder brakes for forming corners in sheet material, eg. sheet metal. Such folder brakes are used in the formation of bodies of cabinets for domestic appliances, the bodies formed thereby usually having sharp corners. In previously proposed folder brakes, there is provided a bed on which the material to be folded is clamped by a suitable cla-mp which extends to -a fulcrurn point .about which a bending leaf is turned to produce a sharp corner in the material.

An object of the present invention is to provide an improved construct-ion of folder brake which will enable radius corners to be produced as well as sharp corners.

According to the present invention there is provided a folder brake comprising .a surface against which a sheet of material can be clamped, pivotal bending means arranged to be pivoted to engage a portion of the sheet and to bend same relative to the remainder of the sheet about a former, said pivotal movement taking place about a fulcrum which is adjustable as to its distance from the clamping surface whereby a sharp corner or a radius corner can be formed on a sheet as desired.

An embodiment of the invention will now be described,

f by way of example, with reference to the accompanying drawings in which:

EGURE 1 is a front View of one form of folder brake,

FIGURE 2 is an end view of Vthe folder brake shown in FIGURE l,

FIGURE 3 is a detail perspective view of the radius adjustment mechanism of the folder brake of FIGURES l and 2,

FlGURE 4 is a diagrammatic side View illustrating mechanism for form-ing a sharp corner on a sheet of metal, and

FIGURE 5 is a diagrammatic side view illustrating mechanism for forming a radius corner on a sheet of metal.

Referring to the FIGURES 1 to 3 of the drawings, a folder brake comprises a rigidly fixed clamp bed 6 on to which can be passed individual metal sheets. Located above the bed 6 is a clamp plate 8 (FlGURl-ES 2, 4 and 5) secured to one arm of a pair of bell crank levers 9, l() each pivotally mounted at 11 and 12 lrespectively within the housing 13 of the folder brake. The other arms of each lever 9, 1d are interconnected by a turnbuckle mechanism 14 whereby the clamp plate 8 can be adjusted as required so .as to be parallel to the clamp -bed 6. When a metal sheet is passed on to the clamp bed 6, the clamp plate 8 is lowered to clamp the sheet against the bed 6 and is raised when the sheet is to be removed from the machine. The raising and lowering of the plate 8 is effected by a pneumatic-ally operated piston and cylinder arrangement. The outer end of the piston 15 is pivotally connected to one end of a pair of links 16, 17, of which link 16 is connected at its other end to one arm of bell crank lever lt) and link 1'7 is pivotally secured to a xed member 18 on the housing 13. On actuation of the piston and cylinder arrangement by means of a. foot pedal 19, the piston 15 rises out of its cylinder and through link 16 and the turnbuckle i4, causes anti-clockwise movement of the bell crank levers 9 and lil about United States Patent C) hidddd Patented June l5, 1365 their pivots 11 and 12 respectively thereby urging the clamp plate S downwards towards the clamp bed 6. To raise the plate S the above procedure is reversed.

Parallel .to the clamp bed 6 there is a bending leaf 26. The bending lead 2t) is supported by a pair of adjustable hinges 21 as shown best in FIGURE 3. One arm 21a of each hinge has a pair of vertical slots 22 therein through each of which passes a bolt 23 secured to a fixed member of the machine, a lock nut Zdbeing provided for each bolt to enable the arm 21a to be locked in a given position by tightening the lock nuts Z4. An internally screwthreaded hexagonal sleeve 25 is provided on a screwthreaded spindle 26 secured to the arm 21a. By loosening the nuts 2d and screwing .the sleeves 25 on each hinge 2l in one or the other direction each `arm 2l and hence the fulcrum point of each hinge as indicated at 27 can be raised or lowered. The second arm Zib of each of the two hinges 21 also has a pair of vertical slots 28 through each of which passes bolts 29 to enable a crossbearn 30, to which the bending leaf 20 is secured and which extends between the two hinges 2l, to be Secured thereto by means of lock nuts (not shown). At each end of the crossbeam 3d there is rotatably secured a downwardly extending, externally screw-threaded spindle 3l which passes through Va screw-threaded hole in a lateral extension 21C of the hinge arm 2lb. By loosening the lock nuts on the bolts 29 and screwing the spindle 3l in one or other direction the level of the surface of the bending leaf 2@ relative to the surface of the clamp bed 6 can be adjusted.

Pivotably mounted on the crossbeam 3d is the free end of the piston 32 of a second pneumatically operated piston .and cylinder arrangement of which the cylinder 33 is pivotably mounted at its bottom end on a sliding member 3d arranged to be slidable between guides 35. A screw adjustment mechanism 35 allows the sliding meinber 34 and hence the bottom end of the cylinder 33 to be moved horizontally to any given fixed position within the extent of the yadjustment mechanism 36. The piston 32 and cylinder 33 are operated by 4the foot pedal 19 which, as described above, also causes actuation of the piston 15.

The operation of the folder brake will now be described, with particular refercnce to FGURES 4 and 5.

The arrangement shown in FIGURE 4 illustrates the folder brake adapted to form sharp corners on a metal sheet. Before feeding any sheet to the machine a former in the nature of a detachable nose piece 37 is attached to the clamp plate 8 by any suitable known means. The nose piece 37 extends along the length of one edge of the clamp plate 8 and has a sharp corner 37a at the point around which the metal sheet 38 is to be bent. The arm 21a of each of the hinges Z1 is then adiusted so that the hinge fulcrum point 27 lies in the same horizontal plane as the surface of the clamp bed 6. The arms 2lb of the hinges are then adjusted to bring the surface of the bending leaf Zit level with the surface of the clamp bed 6. A. metal sheet is then fed onto the clamp bed d with a portion which is to form the turned up flange of the bent sheet overlapping on to the bending leaf 2d. The clamp plate S is then lowered by means of the mechanism described above to clamp the sheet 3S firmly in position. The piston 32 and cylinder 33 are then operated. The piston extends and turns the bending leaf 2t) from the position shown in full lines in FIGURE 4 to the position shown in dotted lines. By this movement the sheet 38 is bent to the position also shown dotted. The bending leaf 20 is then returned to its lowered position, the clamp plate 8 is raised and the sheet 38 removed.

ln FIGURE 5 the sharp nose piece is replaced by a former in the nature of a detachable nose piece 37 inserted and clamped in position'as before.

rounded yin cross-section. Thisrounded'nose piece( is used when itis desired to bend metal sheets so as'to bendingmeans to be aligned with the clamping surface form radius corners.'y When it is desired to form a corf ner of given radius, a nose piece is selected whose rounded nose has that'radius. VThe arms 21a of the hinges y2.1

are then adjusted untilrthe ulcrum point 27 of the hinges are above the clamp bed 6 by a distance equal to the desired radius. The arms 2lb of each hinge are then adjusted to bring the surface kof'the bending leaf level with the clamp bed surface. A metal sheet 138 is Thebending leaf 20 is then turned by extension of the piston 32 :from the position shown in full linesY in FIGURE' 5 tothe position shown in dotted lines, such `turning Inovement causing bending of` the metal sheet 38 by a wiping action Whereby'a'corner of the required radius is formed. Depending on what radius is required, the adjustrnent mechanism '36 is used to vary the position of the bottom of the cylinder 33st; that fullextension *of` the VpistonSZ takes place. Y

It will be apparent that any number of adjustable hinges 211 can be employed so long asfthe'y` kdo n ot ob-` struct operation of the machine.

Whatv I claim is:

tion on the sheet material and selected from a plurality of formers shaped to allow the formation of sharp and radiussed corners, Va pivotal bending means for bending the sheet material about the former, a mounting disposed below theV clamping surface and providing a ulcrum about which thebending means canrpivot comprising at least one hinge having two arms, first yconnecting means adjustably securing'the bending means to one arm of the hinge whereby thedistance'of the bending means from the fulcrum of the h inge can be varied to .enablethe v1. A folder brake comprising arsurface against whichv a sheet of material can be clamped, aY former for 1oca Y before commencement of the bending operation, second connecting means,l adjustably securing the'other `arm vof the hinge to a fixed part of the folder brake'whereby the fdistance of the fulcrum of the hinge fromthe clamping surface can be varied in raccordance with dimensions and shape of Athe corner to be Aproduced on the sheet,

' to the length-of the -sheet being bent.

said rst and second connecting means each comprising at least one through slot in each arm ofthe hinge, a bolt Ypassing through each slot Iand a lock nut for veach bolt so that upon loosening of the lockynutV the arm can be Vmoved within theextent of the slot, and a screw mechanis'rn associated Witheacharm and adjustable to move the hinge arms within 4the extent of each slot.

n 2. A folder brake as claimed in claim` 1, in which the bending means isa plane leaf'of a length at least equal 3. Afolder'brake as claimed in claim 2, comprising aclampplatefor clamping the sheet Iof material in position, and a pneumatically-operatedpiston-and-cylinder device connected tothe Vclamp plate by bell'crank levers for raising Vand lowering the clamp plate.'A

"Arfolder brake as claimed in claim 3, comprising a pneumatically-operated piston-and-cylinder. device connected to-the bending means for pivoting' same and being positionfadjustable depending yon theV lshape ofthe former .l CHARLES W. LANHAM, Primary Examiner.

,WILLIAML STEPHENSON, Examiner. v 

1. A FOLDER BRAKE COMPRISING A SURFACE AGAINST WHICH A SHEET OF MATERIAL CAN BE CLAMPED, A FORMER FOR LOCATION ON THE SHEET MATERIAL AND SELECTED FROM A PLURALITY OF FORMERS SHAPED TO ALLOW THE FORMATION OF SHARP AND RADIUSSED CORNERS, A PIVOTAL BENDING MEANS FOR BEINDING THE SHEET MATERIAL ABOUT THE FORMER, A MOUNTING DISPOSED BELOW THE CLAMPING SURFACE AND PROVIDING A FULCRUM ABOUT WHICH THE BENDING MEANS CAN PIVOT COMPRISING AT LEAST ONE HINGE HAVING TWO ARMS, FIRST CONNECTING MEANS ADJUSTABLY SECURING THE BENDING MEANS TO ONE ARM OF THE HINGE WHEREBY THE DISTANCE OF THE BENDING MEANS FROM THE FULCRUM OF THE HINGE CAN BE VARIED TO ENABLE THE BENDING MEANS TO BE ALIGNED WITH THE CLAMPING SURFACE BEFORE COMMENCEMENT OF THE BENDING OPERATION, SECOND CONNECTING MEANS ADJUSTABLY SECURING THE OTHER ARM OF THE HINGE TO A FIXED PART OF THE FOLDER BRAKE WHEREBY THE DISTANCE OF THE FULCRUM OF THE HINGE FROM THE CLAMPING SURFACE CAN BE VARIED IN ACCODANCE WITH DIMENSIONS AND SHAPE OF THE CORNER TO BE PRODUCED ON THE SHEET, SAID FIRST AND SECOND CONNECTING MEANS EACH COMPRISING AT LEAST ONE THROUGH SLOT IN EACH ARM OF THE HINGE, A BOLT PASSING THROUGH EACH SLOT AND A LOCK NUT FOR EACH BOLT SO THAT UPON LOOSENING OF THE LOCK NUT THE ARM CAN BE MOVED WITHIN THE EXTENT OF THE SLOT, AND A SCREW MECHANISM ASSOCIATED WITH EACH ARM AND ADJUSTABLE TO MOVE THE HINGE ARMS WITHIN THE EXTENT OF EACH SLOT. 